my bro-in-laws 05 has an occasional shudder around 45 mph. it only happens if you're at a constant speed and the auto trans is in top gear. if you touch the gas or brake it goes away. If you have the trans in a lower gear, it won't happen. if you are gently accelerating through that mph range it won't do it. and it won't do it every time. he says the front suspension/steering is in good shape (haven't been able to inspect that for myself yet). I've driven it though, and must say it's a shudder rather than a shimmy or a shake. doesn't feel like any tire imbalance I've experienced. It's very weird.
thought? ideas?
thanks,
--Pete